Patterns of family health insurance coverage are changing, and the consequences of these changes for children are not well understood. Although children's public health insurance has been expanded in many states, little is known about how changes in family / parental insurance coverage affect children's healthcare. We propose to determine how changing patterns of family insurance affect children's health insurance stability and their utilization of healthcare services. We will study how two unique Oregon Health Plan (OHP) policy changes affected children: the loss of public coverage for >50,000 adults in 2003, and the random selection of 10,000 adults to gain OHP coverage in 2008 (Aim 1). We will extend our findings by conducting a national assessment (Aim 2), as we have done successfully with Oregon-based research in the past. We propose to test the following central hypotheses: (1) Children's insurance stability and utilization of recommended healthcare services (such as immunization, well-child visits, receipt of preventive screenings), will differ in association with their parents' insurance coverage status / type, independent of child coverage; (2) Children's insurance stability and utilization patterns will be differentially affected when parents gain or lose coverage; (3) Having a usual source of care will mitigate some of these differences. Our aims and brief methods include: Aim 1: To assess the impact of 2003 and 2008 OHP policy changes on children's health insurance stability and utilization of healthcare services, we propose to use an innovative mixed-methods approach. We will create a linked dataset between OHP administrative data and electronic health record data from a network of over 100 Oregon safety net clinics. We will then conduct quantitative analyses of this linked dataset enriched by concurrent qualitative analyses of in-depth interviews with key informants and low-income families. Aim 2: To test how changing national family health insurance patterns affect children's health insurance stability and their utilization of healthcare services, we will conduct secondary analyses of the Medical Expenditure Panel Survey (MEPS) Household Component. We will build on our expertise in pooling data years and linking children with parents, to better understand family insurance dynamics and longitudinal trends over time. This innovate project uses mixed methods to examine Oregon's natural policy experiments, including the 2008 Medicaid 'lottery.' Oregon's experience will be interpreted within the national context, informing longitudinal analyses of MEPS data. As national health insurance reforms are implemented, understanding the impact of changing patterns of family coverage on children's health will become even more important; thus, this project is timely, relevant, and well-positioned to inform state and national health policy debates.